New research suggests a potential link between high consumption of artificial sweeteners and a decline in cognitive function, particularly among adults under 60. A large Brazilian study, following over 12,000 middle-aged adults, found that those who consumed the most artificial sweeteners experienced significantly faster declines in memory and thinking skills. The effect was comparable to approximately 1.6 years of extra brain aging, according to findings published in , in the journal Neurology.
Sweeteners and Cognitive Decline: What the Study Found
Researchers tracked the consumption of seven artificial sweeteners commonly found in ultra-processed foods such as flavored water, soda, energy drinks, yogurt, and low-calorie desserts. Participants were divided into groups based on their intake levels. The lowest consumption group averaged 20 milligrams per day (mg/day), while the highest group averaged 191 mg/day. For context, 191 mg/day of aspartame is roughly equivalent to the amount found in one can of diet soda.
The study revealed that individuals in the highest consumption group exhibited a faster decline in overall thinking and memory skills compared to those in the lowest consumption group. This accelerated decline equated to about 1.6 years of cognitive aging. Importantly, the association was primarily observed in participants under the age of 60. No significant link was found in those over 60.
Aspartame and Other Sweeteners Under Scrutiny
While the study identified a correlation, it’s crucial to understand that it does not definitively prove that artificial sweeteners cause cognitive decline. Correlation does not equal causation, and further research is needed to establish a causal relationship. The researchers acknowledge this limitation, emphasizing that other factors could contribute to the observed cognitive changes.
The sweeteners examined in the study included aspartame and saccharin, both widely used in food and beverage products. The World Health Organization (WHO) and the Food and Agriculture Organization (FAO) recently released assessments of aspartame in . The International Agency for Research on Cancer (IARC) classified aspartame as “possibly carcinogenic to humans” (Group 2B), citing limited evidence of cancer risk in humans. However, the Joint Expert Committee on Food Additives (JECFA) reaffirmed the acceptable daily intake (ADI) of aspartame at 40 mg/kg of body weight.
According to the JECFA assessment, an adult weighing 70kg would need to consume more than 9-14 cans of diet soft drink containing 200-300 mg of aspartame per can to exceed the acceptable daily intake, assuming no other sources of aspartame in their diet. This suggests that, for most people, typical consumption levels of aspartame are unlikely to pose a significant health risk based on current guidelines.
Methanol Concerns and Aspartame Metabolism
Past concerns regarding aspartame have centered on its metabolism and the potential release of methanol. Some early studies suggested that methanol intake from diet soda could exceed recommended limits. However, more recent estimates, as noted in a publication in Nutrients, indicate that realistic methanol intake from daily aspartame consumption is likely lower than previously estimated.
What Does This Mean for Consumers?
The findings of the Brazilian study add to the growing body of research examining the potential health effects of artificial sweeteners. While the current evidence does not warrant drastic changes in dietary habits, it does highlight the importance of moderation and awareness. Individuals concerned about their cognitive health, particularly those under 60 and those with diabetes, may wish to consider reducing their intake of foods and beverages containing artificial sweeteners.
It’s important to remember that a healthy lifestyle, including a balanced diet, regular exercise, and sufficient sleep, plays a crucial role in maintaining cognitive function. Focusing on these foundational elements of health is likely to have a more significant impact than solely eliminating artificial sweeteners.
Further research is needed to fully understand the complex relationship between artificial sweeteners and cognitive health. Ongoing studies will help clarify the potential risks and benefits, and inform future dietary recommendations. For now, a cautious and informed approach to sweetener consumption is advisable.
